I have a 1993 long bed 4x4 t100 1/2 ton. Can I put a rear axle from a 1 ton model into it? And will this effect the 4x4?

 

You can physically do anything, that being said, the only issue I see is the gearing of the new rearend must match the gearing of the front axle or you will hear a big POW when you try to drive it in 4 wheel drive.
I'm not familiar enough with Toy axles to know what gears the one ton might have in it or for the stock axle gears either. I have reg-geared a few axles, you can be up to 10% off safely (some trucks used to come that way because of the limited size of the actual center sections)
One other thing to consider is the wheel bolt patterns will be different (assuming that one tons have larger everything)
good luck!

 

Just the axles or the whole axle housing?

The axles are the same across the year groups and drive train. The only difference if you have ABS or not.

If yer talking about the whole axle housing, the difference is the spring perches. You can cut off the existing ones and weld in the new ones.

The differential thirds will swap over without any problems...so you can swap yer current third over to the next housing.